Mode Stirred Chamber Measurement of GHz Emissions of Wireless Power Transfer Systems

This paper shows measurements of emissions from a wireless power transmission system (WPT) into the GHz region measured in a mode-stirred reverberation chamber. It estimates the disturbance potential of these signals relative to the needed signal strengths of wireless communication systems, such as GPS. It is explained how to measure pulsed signals in a mode stirred chamber by using triggered spectral analysis and averaging by mechanical mode stirring. Based on this measurement and analysis it is possible to estimate the loss in the signal budget due to this interference for wireless data such as Bluetooth, GPS, or Wi-Fi. The primary objective is to use this example to illustrate that these low clock frequency, fast switching GaN devices can disturb wireless services and how to quantify the radiation and disturbance potential using a mode stirred chamber. GaN, Si, and SiC implementations are compared.